A034870 → basis A013611

nonnegative coefficients only rational roots

Proved for all n: all roots real, in (−∞, 0] · coefficients of one sign · Hadamard kernel what this means

Recurrence
\(P_{n}(x) = \left(4 + 16\,x + 16\,x^{2}\right)\,P_{n-1}(x)\)
\(P_{0}(x) = 1\)

Rows ?

nx0x1x2x3x4x5x6x7x8x9x10x11x12x13x14Pn(1)
011
14161636
2161283845122561296
3647683840102401536012288409646656
4256409628672114688286720458752458752262144655361679616
5102420480184320983040344064082575361376256015728640117964805242880104857660466176
64096983041081344720896032440320103809024242221056415236096519045120461373440276824064100663296167772162176782336
716384458752596377647710208262406144104962457631488737287197425664125954949121679399321616793993216122138132486106906624187904819226843545678364164096

Generated b-files: A009980 (row sums) ?

Computed in your browser ?

Technical details
Node id
n-0ca8dc857c80d449 · revision 1 · JSON
Definition source
derived:basis_map_A013611
Fingerprint
f6-90334921cba1a1bb

Observed on the stored rows ?

  • Degrees: 0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28 (affine: slope 2, intercept 0)
  • Palindromic rows: no
  • γ-positive (gamma_positive): no
  • Nonnegative coefficients (nonn): yes
  • Only rational roots (rr_by_factors: every nonzero row is a product of linear factors over ℚ): yes

OEIS matches ?

A generated b-file is computed from the node's definition along the row alignment of its OEIS link and starts at the entry's offset. It is an identification on a finite prefix, not a proof that the node and the OEIS entry agree for every n.

OEIS submission text ?

Fields to paste into an OEIS submission: the example %e, the formula %F and programs %t (Mathematica) and %o (PARI/GP) that list the same rows. For an OEIS link the row numbers, the offset and the orientation are those of the entry, as matched; the matched terms were compared with the published ones, which identifies the node with the entry on a finite prefix, not for every n. The PARI/GP program is not machine-checked here.

The atlas's own rows: n = 0, …, ascending powers of x
%e Example
Triangle begins:
  0:      1;
  1:      4,      16,        16;
  2:     16,     128,       384,        512,         256;
  3:     64,     768,      3840,      10240,       15360,       12288,         4096;
  4:    256,    4096,     28672,     114688,      286720,      458752,       458752,        262144,         65536;
  5:   1024,   20480,    184320,     983040,     3440640,     8257536,     13762560,      15728640,      11796480,       5242880,        1048576;
  6:   4096,   98304,   1081344,    7208960,    32440320,   103809024,    242221056,     415236096,     519045120,     461373440,      276824064,      100663296,       16777216;
  7:  16384,  458752,   5963776,   47710208,   262406144,  1049624576,   3148873728,    7197425664,   12595494912,   16793993216,    16793993216,    12213813248,     6106906624,     1879048192,      268435456;
  8:  65536, 2097152,  31457280,  293601280,  1908408320,  9160359936,  33587986432,   95965675520,  215922769920,  383862702080,   537407782912,   586263035904,   488552529920,   300647710720,   128849018880,   34359738368,    4294967296;
  9: 262144, 9437184, 160432128, 1711276032, 12834570240, 71873593344, 311452237824, 1067836243968, 2936549670912, 6525665935360, 11746198683648, 17085379903488, 19932943220736, 18399639896064, 13142599925760, 7009386627072, 2628519985152, 618475290624, 68719476736;
%F Formula
The row polynomials satisfy P(n,x) = (4+16*x+16*x^2)*P(n-1,x) for n >= 1, with P(0,x) = 1.
%t Mathematica
P[0, x_] := 1;
P[n_, x_] := P[n, x] = Expand[(4 + 16*x + 16*x^2)*P[n - 1, x]];
Table[CoefficientList[P[n, x], x], {n, 0, 9}] // Flatten
%o PARI/GP
P(N) = {my(v = vector(N + 1)); v[1] = 1; for(n = 1, N, my(i = n + 1); v[i] = (4 + 16*x + 16*x^2)*v[i - 1]); v};
row(n, p) = {my(c = Vecrev(p)); c};
T(N) = {my(v = P(N)); concat(vector(#v, i, row(i - 1, v[i])))};
T(9)

Generated with polytool c48629374597.

Proved properties

  • Real-rooted. Every row P_n, n >= 0, is zero or real-rooted with all roots in (-inf, 0]
    Every polynomial of the sequence has only real roots, inside the stated interval.
    by the cited steps: e-a6b5412d61e1c4e3
  • Coefficients of one sign. Every nonzero row, n >= 0: the coefficients of P_n have one sign
    All coefficients of each polynomial have the same sign (after x -> -x when alternating).
    derived from the cited steps by a stated theorem: e-a6b5412d61e1c4e3
  • Hadamard kernel (Malo). Rows P_n, n >= 0, are Hadamard kernels (preserve real-rootedness)
    Multiplying the coefficients of any real-rooted polynomial termwise by those of a row (Hadamard product) gives a real-rooted polynomial again.
    derived from the cited steps by a stated theorem: e-a6b5412d61e1c4e3

Proof chains

1 incoming proof step. Each step is expanded back to the roots of the proof DAG, the theorem checks of a node's own rule. JSON

Same fingerprint (5)

Equal up to content, sign, reversal and a small index shift.